Tag Archives: Guanosine Triphosphate

In this video, you will see just how toxic mercury really is and how it causes damage to the brain.

Quoted from the video:

“Shown here is the neurite of a live neuron isolated from snail brain tissue displaying linear growth due to growth cone activity.

It is important to note that growth cones in all animal species, ranging from snails to humans, have identical structural and behavioral characteristics, and use proteins of virtually identical composition.

In this experiment, neurons also isolated from snail brain tissue were grown in culture for several days. Afterwhich, very low concentrations of mercury (30 micrograms) were added to the culture medium for 20 minutes.

Over the next 30 minutes, the neuron underwent rapid degeneration leaving the denuded neurofibrils seen here.

To understand how mercury causes this degeneration, let us return to our illustration. As mentioned before, tubulin proteins link together during normal cell growth to form microtubules which support the neurite structure.

When mercury ions are introduced into the culture medium, they infiltrate the cell and bind themselves to newly synthesized tubulin molecules.

More specifically, the mercury ions attach themselves to the binding sites reserved for Guanosine Triphosphate (GTP) on the beta subunit of the affected tubulin molecules.

Since bound GTP normally provides the energy which allows tubulin molecules to attach to one another, mercury ions bound to these sites prevent tubulin proteins from linking together.

Consequently, the neurite’s microtubules begin to disassemble into free tubulin molecules, leaving the neurites stripped of its support structure.

Ultimately, both the developing neurite and its growth cone collapse, and some denuded neurofibrils form aggregates, or tangles, as depicted here.

Shown here is a neurite growth cone stained specifically for tubulin and actin, before and after mercury exposure.

Note that the mercury has caused disintigration of tubilin microtubule structure.

These new findings reveal important visual evidence as to how mercury causes neuro-degeneration.

More importantly, this study provides the first direct evidence that low-level mercury exposure is indeed a precipitating factor that can initiate this neuro-degenerative process within the brain.”